The present embodiments relate to a network node, to a control module for a component, and to an Ethernet ring.
Redundant systems having a “fail operational” behavior, for example, are very important (e.g., in connection with autonomous driving). Autonomous driving comes into consideration for electric vehicles, for internal combustion engine vehicles, and for hybrid vehicles as well as for special vehicles (e.g., forklift trucks in production halls). Fly-by-wire systems and autopilots are already used in aviation, but the systems used in aviation are too expensive for use in automobiles.
Redundant systems are also used in other areas (e.g., in the control of industrial installations, power plants, railroad crossings, etc.). For reasons of cost, a system is often not made “fail operational” if a safe state may be assumed and a “fail silent” behavior is therefore sufficient. A railroad crossing would close in the event of a fault, for example. The railroad crossing system would be safe in this example, but would no longer function.
In the event of any individual fault, “fail operational” systems are able to detect and isolate this fault and are still able to function, at least for a particular time. This time may be used to safely approach the next parking lot (e.g., in the automobile) or to repair the components that have failed and therefore provide interruption-free operation in an industrial installation.
Fail operational systems are to be used if there is no safe state (e.g., if a vehicle cannot easily stop on the highway). Fail operational systems may be used to increase the availability of a system. In this case, the costs for the fail operational configuration are to be compared with the costs for a possible failure.